diff options
Diffstat (limited to 'dump.c')
| -rw-r--r-- | dump.c | 183 |
1 files changed, 183 insertions, 0 deletions
@@ -25,6 +25,8 @@ #include "qapi/qmp/qerror.h" #include "qmp-commands.h" #include "qapi-event.h" +#include "qemu/error-report.h" +#include "hw/misc/vmcoreinfo.h" #include <zlib.h> #ifdef CONFIG_LZO @@ -37,6 +39,13 @@ #define ELF_MACHINE_UNAME "Unknown" #endif +#define MAX_GUEST_NOTE_SIZE (1 << 20) /* 1MB should be enough */ + +#define ELF_NOTE_SIZE(hdr_size, name_size, desc_size) \ + ((DIV_ROUND_UP((hdr_size), 4) + \ + DIV_ROUND_UP((name_size), 4) + \ + DIV_ROUND_UP((desc_size), 4)) * 4) + uint16_t cpu_to_dump16(DumpState *s, uint16_t val) { if (s->dump_info.d_endian == ELFDATA2LSB) { @@ -75,6 +84,8 @@ static int dump_cleanup(DumpState *s) guest_phys_blocks_free(&s->guest_phys_blocks); memory_mapping_list_free(&s->list); close(s->fd); + g_free(s->guest_note); + s->guest_note = NULL; if (s->resume) { if (s->detached) { qemu_mutex_lock_iothread(); @@ -234,6 +245,19 @@ static inline int cpu_index(CPUState *cpu) return cpu->cpu_index + 1; } +static void write_guest_note(WriteCoreDumpFunction f, DumpState *s, + Error **errp) +{ + int ret; + + if (s->guest_note) { + ret = f(s->guest_note, s->guest_note_size, s); + if (ret < 0) { + error_setg(errp, "dump: failed to write guest note"); + } + } +} + static void write_elf64_notes(WriteCoreDumpFunction f, DumpState *s, Error **errp) { @@ -257,6 +281,8 @@ static void write_elf64_notes(WriteCoreDumpFunction f, DumpState *s, return; } } + + write_guest_note(f, s, errp); } static void write_elf32_note(DumpState *s, Error **errp) @@ -302,6 +328,8 @@ static void write_elf32_notes(WriteCoreDumpFunction f, DumpState *s, return; } } + + write_guest_note(f, s, errp); } static void write_elf_section(DumpState *s, int type, Error **errp) @@ -713,6 +741,61 @@ static int buf_write_note(const void *buf, size_t size, void *opaque) return 0; } +/* + * This function retrieves various sizes from an elf header. + * + * @note has to be a valid ELF note. The return sizes are unmodified + * (not padded or rounded up to be multiple of 4). + */ +static void get_note_sizes(DumpState *s, const void *note, + uint64_t *note_head_size, + uint64_t *name_size, + uint64_t *desc_size) +{ + uint64_t note_head_sz; + uint64_t name_sz; + uint64_t desc_sz; + + if (s->dump_info.d_class == ELFCLASS64) { + const Elf64_Nhdr *hdr = note; + note_head_sz = sizeof(Elf64_Nhdr); + name_sz = tswap64(hdr->n_namesz); + desc_sz = tswap64(hdr->n_descsz); + } else { + const Elf32_Nhdr *hdr = note; + note_head_sz = sizeof(Elf32_Nhdr); + name_sz = tswap32(hdr->n_namesz); + desc_sz = tswap32(hdr->n_descsz); + } + + if (note_head_size) { + *note_head_size = note_head_sz; + } + if (name_size) { + *name_size = name_sz; + } + if (desc_size) { + *desc_size = desc_sz; + } +} + +static bool note_name_equal(DumpState *s, + const uint8_t *note, const char *name) +{ + int len = strlen(name) + 1; + uint64_t head_size, name_size; + + get_note_sizes(s, note, &head_size, &name_size, NULL); + head_size = ROUND_UP(head_size, 4); + + if (name_size != len || + memcmp(note + head_size, "VMCOREINFO", len)) { + return false; + } + + return true; +} + /* write common header, sub header and elf note to vmcore */ static void create_header32(DumpState *s, Error **errp) { @@ -774,6 +857,18 @@ static void create_header32(DumpState *s, Error **errp) kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL); offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size; + if (s->guest_note && + note_name_equal(s, s->guest_note, "VMCOREINFO")) { + uint64_t hsize, name_size, size_vmcoreinfo_desc, offset_vmcoreinfo; + + get_note_sizes(s, s->guest_note, + &hsize, &name_size, &size_vmcoreinfo_desc); + offset_vmcoreinfo = offset_note + s->note_size - s->guest_note_size + + (DIV_ROUND_UP(hsize, 4) + DIV_ROUND_UP(name_size, 4)) * 4; + kh->offset_vmcoreinfo = cpu_to_dump64(s, offset_vmcoreinfo); + kh->size_vmcoreinfo = cpu_to_dump32(s, size_vmcoreinfo_desc); + } + kh->offset_note = cpu_to_dump64(s, offset_note); kh->note_size = cpu_to_dump32(s, s->note_size); @@ -874,6 +969,18 @@ static void create_header64(DumpState *s, Error **errp) kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL); offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size; + if (s->guest_note && + note_name_equal(s, s->guest_note, "VMCOREINFO")) { + uint64_t hsize, name_size, size_vmcoreinfo_desc, offset_vmcoreinfo; + + get_note_sizes(s, s->guest_note, + &hsize, &name_size, &size_vmcoreinfo_desc); + offset_vmcoreinfo = offset_note + s->note_size - s->guest_note_size + + (DIV_ROUND_UP(hsize, 4) + DIV_ROUND_UP(name_size, 4)) * 4; + kh->offset_vmcoreinfo = cpu_to_dump64(s, offset_vmcoreinfo); + kh->size_vmcoreinfo = cpu_to_dump64(s, size_vmcoreinfo_desc); + } + kh->offset_note = cpu_to_dump64(s, offset_note); kh->note_size = cpu_to_dump64(s, s->note_size); @@ -1487,10 +1594,44 @@ static int64_t dump_calculate_size(DumpState *s) return total; } +static void vmcoreinfo_update_phys_base(DumpState *s) +{ + uint64_t size, note_head_size, name_size, phys_base; + char **lines; + uint8_t *vmci; + size_t i; + + if (!note_name_equal(s, s->guest_note, "VMCOREINFO")) { + return; + } + + get_note_sizes(s, s->guest_note, ¬e_head_size, &name_size, &size); + note_head_size = ROUND_UP(note_head_size, 4); + + vmci = s->guest_note + note_head_size + ROUND_UP(name_size, 4); + *(vmci + size) = '\0'; + + lines = g_strsplit((char *)vmci, "\n", -1); + for (i = 0; lines[i]; i++) { + if (g_str_has_prefix(lines[i], "NUMBER(phys_base)=")) { + if (qemu_strtou64(lines[i] + 18, NULL, 16, + &phys_base) < 0) { + warn_report("Failed to read NUMBER(phys_base)="); + } else { + s->dump_info.phys_base = phys_base; + } + break; + } + } + + g_strfreev(lines); +} + static void dump_init(DumpState *s, int fd, bool has_format, DumpGuestMemoryFormat format, bool paging, bool has_filter, int64_t begin, int64_t length, Error **errp) { + VMCoreInfoState *vmci = vmcoreinfo_find(); CPUState *cpu; int nr_cpus; Error *err = NULL; @@ -1568,6 +1709,48 @@ static void dump_init(DumpState *s, int fd, bool has_format, goto cleanup; } + /* + * The goal of this block is to (a) update the previously guessed + * phys_base, (b) copy the guest note out of the guest. + * Failure to do so is not fatal for dumping. + */ + if (vmci) { + uint64_t addr, note_head_size, name_size, desc_size; + uint32_t size; + uint16_t format; + + note_head_size = s->dump_info.d_class == ELFCLASS32 ? + sizeof(Elf32_Nhdr) : sizeof(Elf64_Nhdr); + + format = le16_to_cpu(vmci->vmcoreinfo.guest_format); + size = le32_to_cpu(vmci->vmcoreinfo.size); + addr = le64_to_cpu(vmci->vmcoreinfo.paddr); + if (!vmci->has_vmcoreinfo) { + warn_report("guest note is not present"); + } else if (size < note_head_size || size > MAX_GUEST_NOTE_SIZE) { + warn_report("guest note size is invalid: %" PRIu32, size); + } else if (format != VMCOREINFO_FORMAT_ELF) { + warn_report("guest note format is unsupported: %" PRIu16, format); + } else { + s->guest_note = g_malloc(size + 1); /* +1 for adding \0 */ + cpu_physical_memory_read(addr, s->guest_note, size); + + get_note_sizes(s, s->guest_note, NULL, &name_size, &desc_size); + s->guest_note_size = ELF_NOTE_SIZE(note_head_size, name_size, + desc_size); + if (name_size > MAX_GUEST_NOTE_SIZE || + desc_size > MAX_GUEST_NOTE_SIZE || + s->guest_note_size > size) { + warn_report("Invalid guest note header"); + g_free(s->guest_note); + s->guest_note = NULL; + } else { + vmcoreinfo_update_phys_base(s); + s->note_size += s->guest_note_size; + } + } + } + /* get memory mapping */ if (paging) { qemu_get_guest_memory_mapping(&s->list, &s->guest_phys_blocks, &err); |